1. Field of the Invention
The present invention relates generally to injection devices and methods and, more specifically, to needle assemblies for use in injection devices and methods directed to improving compliance with regard to the self administration of drugs.
2. State of the Art
Injection devices are commonly utilized for the delivery of a substance to a patient. Such injection devices conventionally include a container, such as a syringe or a carpule, for holding the material to be injected, means for measuring or dosing the material, a needle or other delivery device for delivering the material into or beneath the patient""s skin, and an actuator for moving the material through the delivery device and into the patient.
Various types of injection devices are available, including devices configured and intended for self-administration or self-injection. Self-injection devices may be commonly used for administering, for example, insulin to a diabetic. Additionally, new drugs and medical treatments are suited for self administration via injection.
An issue associated with treatment involving self-injection is ensuring patient compliance. For example, even though a treatment has been prescribed, a patient may not fully comply for various reasons, including, for example, the inability to properly operate the injection device due to its complexity or due to the physical limitations of the patient. Additionally, patient compliance is often difficult to ensure simply because of the patient""s apprehension in injecting a needle into their own skin.
Another issue associated with self-injection includes the handling of the injection device and the possibility of inadvertent needle sticks either prior to or after the administration of the injection. Such inadvertent needle sticks further add to the apprehension of the user.
One device intending to deal with such issues is disclosed in U.S. Pat. No. 5,609,577 to Haber et al., issued Mar. 11, 1997, and which is incorporated by reference herein. The Haber patent discloses a device which includes a self-locking mechanism to help prevent inadvertent needle sticks. Specifically, the Haber patent discloses the use of a shield formed about the needle to hide the needle from view of a patient. However, the device disclosed by the Haber patent still allows for view of the needle through the end of the shield and, further, allows view and access to the needle during preparation, as the needle needs to be removed and replaced for each individual injection. Thus, even though users may not see the needle immediately prior to injection, they may still view the needle while installing or removing a needle or may view an installed needle by looking through the end of the shield. Thus, while the device disclosed by the Haber patent may be useful in hiding the needle from the view from a patient receiving an injection administered by another, those who are practicing self-injection will ultimately view the needle and may suffer apprehension leading to noncompliance in some individuals. Additionally, while the Haber patent discloses a locking mechanism to prevent inadvertent needle sticks when the needle is installed on the injection device, such needle sticks may still occur during the removal and replacement of the needle from the injection device.
In view of the shortcomings in the art, it would advantageous to provide a needle assembly which improves user compliance by concealing the injection needle from the access and view of a user. Additionally, it would be advantageous to configure such a needle assembly for removable attachment to an injection device. Further, it would be advantageous to provide a needle assembly with one or more locking mechanisms to prevent inadvertent sticks while the needle is coupled to the injection device and also during handling of the needle assembly while it is uncoupled from the injection device.
In accordance with one aspect of the invention, an injection needle assembly is provided. The needle assembly includes a first housing member which has an opening defined therein. A first membrane is disposed on the first housing member so as to cover its opening. A second housing member is coupled to the first housing member and also has an opening defined therein. A second membrane is disposed on the second housing member so as to cover its respective opening. A needle is disposed within the first and second housing members such that the needle is concealed from a user thereof by the first and second housing members and the first and second membranes.
The needle assembly may further be configured such that, upon coupling with an injection device, the first membrane is displaced inwardly of the needle assembly causing the needle to penetrate therethrough.
Additional features may also be incorporated with the needle device, such as safety locking mechanisms. For example, a locking mechanism may be incorporated whereby the first and second housing members are prevented from moving relative to each other prior to coupling of the needle assembly with an injection device. A separate locking mechanism may be utilized to prevent inadvertent actuation of the needle assembly after its coupling with an injection device but prior to intended employment of the injection device.
According to another aspect of the invention, a needle assembly includes a first housing member configured to be removably coupled with an injection device. A first membrane is disposed on and covers an opening at the proximal end of the first housing member. A second housing member is coupled with the first housing member and is longitudinally slidable relative to the first housing member. A second membrane is disposed upon and covers an opening formed in the second housing member. A needle is rigidly fixed to the first housing member disposed within the first and second housing members and concealed by the first and second membranes.